1. Department of Communication Sciences and Disorders, MGH Institute of Health Professions, 36 First Avenue, Boston, MA 02129, USA
2. Department of Speech-Language Pathology, University of Toronto, 160-500 University Avenue, Toronto, ON, Canada M5G 1V7
3. Department of Bioengineering, University of Texas at Dallas, 800 W. Campbell Road, Richardson, TX 75080, USA
4. Callier Center for Communication Disorders, University of Texas at Dallas, 1966 Inwood Road, Dallas, TX 75235, USA